Antidepressant utilization in Canada

Antidepressant utilization can be used as an indicator of appropriate treatment for major depression. The objective of this study was to characterize antidepressant utilization in Canada, including the relationships of antidepressant use with sociodemographic variables, past-year and lifetime depression, number of past depressive episodes, and other possible indications for antidepressants.

We examined data from the Canadian Community Health Survey (CCHS) Cycle 1.2. The CCHS was a nationally representative mental health survey (N=36,984) conducted in 2002 that included a diagnostic instrument for past-year and lifetime major depressive episodes and other psychiatric disorders and a record of past-year antidepressant use.

Overall, 5.8% of Canadians were taking antidepressants, higher than the annual prevalence of major depressive episode (4.8%) in the survey. Among persons with a past-year major depressive episode, the frequency of antidepressant use was 40.4%. After application of adjustments for probable successful outcomes of treatment, the estimated frequency of antidepressant use for major depression was more than 50%. Frequency of antidepressant treatment among those with a history of depression but without a past-year episode increased with the number of previous episodes. Among those taking antidepressants over the past year, only 33.1% had had a past-year episode of major depression. Migraine, fibromyalgia, anxiety disorder, or past depression was present in more than 60% of those taking antidepressants without a past-year episode of depression.

The CCHS results suggest that antidepressant use has increased substantially since the early 1990s, and also that these medications are employed extensively for indications other than depression.